Imam Malik Ibn Anas saw the Death Angel (Malak al-Maut) in his sleep, and the Imam asked him: “How much left for me to live?”
The Angel pointed out to him with his five fingers opening his hand-palm. Then the Imam asked him: “Does that 
mean five years, or five months, or five days?” Before the Imam had a chance to get an answer back, he woke up.
He immediately rushed to make his wudhu and pray two rak’at. He waited but nothing happened. He prayed al-Fajr and he waited. He prayed al-Duha and yet again nothing happened.
The Imam went to Muhammad Ibn Sirin, a well-known interpreter of dreams. That man told him: “Ya Imam Malik, when the Angel pointed out to you with his five fingers, he did not mean five years or months or days. The Angel meant that your question was among the five matters that only Allah knows about.” And then, he recited that ayah.
Indeed, Allah alone has knowledge of the Hour and sends down the rain and knows what is in the wombs. And no soul knows what it will earn tomorrow, and no soul knows in what land it will die. Indeed, Allah is Knowing and Acquainted. (31:34)